The present invention relates generally to the delivery of an object within a patient, wherein the object is delivered in a preferred orientation relative to the delivery site of the patient. More particularly, the present invention relates to a delivery device having an alignment member that allows the object to be delivered intravascularly to the delivery site of the patient, wherein the object is delivered in a predetermined orientation. The object may, for example, be non-symmetric or include a configuration that requires delivery to the site in only one suitable orientation relative to the delivery site. Such objects may be used, for example, to treat certain defects or injuries in vessels or organs within a patient""s body.
Over the years, medical devices delivered intravascularly have been used to treat many types of defects in the tissues and organs of a patient. For example, intra cardiac devices have been used to treat certain congenital defects of the heart including a ventricular septal defect (VSDxe2x80x94a defect or aperture extending through the septum between the left and right ventricles), atrial septal defect (ASDxe2x80x94a defect or aperture extending through the septum between the right and left atrium) or patent ductus arteriosus (PDAxe2x80x94an incomplete closure of an opening between the pulmonary artery and the aorta that is present during fetal development). These conditions may cause blood to abnormally shunt between the heart chambers causing an imbalance in the oxygen levels in the blood causing cyanosis, cardiac enlargement, failure or other complications.
Non-invasive techniques have been developed to treat these defects. These techniques include the use of catheters and guide wires to deliver an occluding device to the desired location within the patient""s heart. These devices may be difficult to position and a nonsymmetric device may prove to be even further challenging to deliver in a preferred orientation. For example, a PDA device may preferably be shaped non-symmetrically to conform to the angle of the communication between the main pulmonary artery and the aorta. In order for this non-symmetric device to be effective, it must be delivered in the communication with a specific orientation so that the retention disc of the device is flush against the aorta wall. As another example, perimembranous ventricular septal defects are typically very close to the aortic valve. For closure of such defects, the retention mechanism must be asymmetrical wherein the retention disc is offset from the center of the device, such that the retention disc extends further out from the main portion on one side than on the other side of the main portion. The smaller portion of the retention disc or rim is oriented toward the aortic valve.
Other defects in blood vessels, for example, may require the delivery of a device into the vessel, wherein a particular orientation of the device within the vessel is required. For example, the device may include an aperture or some other particular configuration requiring delivery of the device in a particular orientation in the vessel. Hence, there is a need for a device and method of delivering an object to a specific site, wherein the orientation of the object is controlled. The present invention meets these and other needs that should be apparent to those skilled in the art.
The device of the present invention is suitable for delivering a collapsible object to a pre-selected region within a patient. An elongated pusher catheter, for example, may be modified to include on its distal end a distal tip having an alignment member adapted for mating with a connecting member of the collapsible object. The elongated pusher catheter may further have a preset curve or bend designed to match the shape or curve of the delivery sheath which roughly matches the shape or curve of the vessel adjacent the delivery site. During delivery of the elongated pusher catheter, the catheter tends to rotate so that the bend in the catheter tends towards alignment with the curve in the vessel. When the collapsible object is attached in a fixed position to the distal tip of the elongated pusher catheter, the orientation of the collapsible object is known relative to the bend in the pusher catheter. In this manner, when the elongated pusher catheter is delivered, the orientation of the collapsible object is known relative to the curve of the delivery catheter and the vessel at the delivery site. Correct orientation can be accomplished by incorporating the same curvature in the pusher catheter and the delivery catheter or by preventing rotation of the delivery pusher in the delivery catheter.
In the preferred embodiment the pusher catheter includes a lumen extending there through between the proximal end and distal end, wherein the distal tip includes an aperture extending there through and aligned with the lumen. A cable extends through the lumen of the pusher catheter, wherein a distal end of the cable is extendable through the aperture of the distal tip and coupleable to the collapsible object. Without limitation, the distal end of the cable includes a threaded outer surface and the collapsible object includes a member having a threaded bore adapted for receiving the threaded outer surface of the cable. Those skilled in the art will appreciate that other methods of releaseably fastening objects together may be incorporated into the distal tip and collapsible object without imparting from the present invention.
The distal tip of the pusher catheter further includes an alignment member having a predetermined shape. The coupling member of the collapsible object includes a corresponding mating shape, such that the collapsible object may only align and engage the alignment member in one orientation. For example, without limitation, the shape of the alignment member may be a semicircular, a square with one beveled comer, an isosceles triangle, or other shape that only allows for one mating orientation. The engagement between the alignment member and connecting or coupling member inhibits the collapsible device from rotating about the distal tip.
In use, a non-symmetric object may be delivered within a patient utilizing the device of the present invention, wherein the orientation of the object is predefined. The user first couples the non-symmetric device to an elongated pusher catheter, wherein the distal tip has an alignment member adapted for mating with a connecting member of the non-symmetric device. The device may include a radiopaque marker attached at a predefined position on the asymmetrical device. In this manner, the orientation of the asymmetrical device may be determined through fluoroscopy or another known manner of observation. The orientation of the alignment member is fixed relative to a bend in the pusher catheter. A delivery sheath is then positioned within the patient""s body vessel, wherein a distal end of the sheath is proximate a desired site of delivery. The sheath may also have a preset bend corresponding to a shape of the vessel proximate the desired site of delivery. Alternatively, the pusher catheter and interior lumen of the sheath may be shaped to prevent rotation of the pusher catheter within the sheath. The user then loads the non-symmetric device coupled to the pusher catheter into the sheath, by connecting the alignment member in an orientation associated with the curve in the pusher catheter. The pusher catheter is then passed through the sheath until the distal tip of the pusher catheter extends out the sheath. The user may then determine whether the collapsible object has been positioned properly and if desired may disengage the object from the alignment member and tip of the pusher catheter. The user may then remove the pusher catheter and sheath in a known suitable fashion.